What is the correct abbreviation for 'three times a day'?

The abbreviation for 'three times a day' is "tid," which stands for the Latin term "ter in die." This term is commonly used in medical prescriptions to indicate the frequency at which a medication should be taken. By using "tid," healthcare providers can succinctly convey to patients or pharmacists that the medication should be administered three times throughout the day, typically spread out evenly.

The other abbreviations serve different purposes: "b.i.d." means "twice a day," which indicates a different dosing schedule; "q.i.d." stands for "four times a day," indicating an even more frequent dosing; and the term "once" does not provide a specific frequency relevant to medical dosing. Understanding these abbreviations is crucial for accurately administering medications and ensuring patient safety.